Most firearms employ a safety mechanism, also known as a “safety” that prevents unintentional firing. In some firearms, the safety is actuated by an actuation bar that is shifted sideways. The FN MAG 58 machine gun is an example of such a firearm, wherein pushing the cross bolt safety lever to the right disables the firing. Moving the lever to the left disengages the safety catch, thereby removing restraints from the trigger.
U.S. Pat. No. 6,253,480 (Florez) discloses a personalized safety device for preventing unauthorized use of a hand held weapon having a trigger. The device includes a housing which is coupled to the weapon such that the housing is positioned in front of the handgrip and trigger of the weapon. A pair of elongate guard plates outwardly extend from a pair of elongate slots in the back of the housing. A motor is disposed in the housing for extending and the retracting the guard plates from the housing. A computer is provided for controlling the retraction and extension of the guard plates by the motor. A scanner is mounted to the handgrip of the weapon and is in communication with the computer. The scanner obtains an image of the fingerprints and handprint of the user grasping the handgrip. If the scanned image matches data stored in the computer corresponding to the fingerprints and handprint of an authorized user, the computer activates the motor to retract the guard plates. The patent device does not directly actuate a trigger safety to allow firing of the weapon.